1. Field of the Invention
The present invention relates to an apparatus for circulating a carrier fluid. More specifically, the present invention relates to an apparatus for circulating a carrier fluid having two or more chambers or sections, an apparatus for amplifying a nucleic acid using the same, and a chip containing the same.
2. Description of the Related Art
A polymerase chain reaction (PCR) method has been developed to amplify nucleic acid sequences by being subject to a periodical hot-cold temperature cycle. In PCR, one cycle of DNA amplification requires a biochemical sample to sequentially be exposed to various temperatures, such as T1 (for denaturing)→T2 (for annealing)→T3 (for extension).
As shown in FIG. 1, a conventional PCR system has a structure where polymerase chain reaction is performed by controlling the temperatures (T1 for denaturing: 94° C., T2 for annealing: 55° C., T3 for extension: 72° C.) of a chamber retaining a biochemical fluid, such as a PCR fluid. In this system, the repetition of heating and cooling the chamber causes a time delay for heating and cooling, thus complicated circuits are needed for an accurate control of the temperatures.
U.S. Pat. No. 5,270,183 discloses an apparatus and method for the amplification of nucleic acids in a sample using the polymerase chain reaction, as shown in FIG. 2, where a polymerase chain reaction is performed by continuously flowing a biochemical fluid, such as a PCR fluid, in zigzags along different temperature zones. Therefore, this system may require an extraordinarily long channel for a biochemical fluid to follow an accurate temperature profile, because the movement from T3 section to T1 section requires passage through T2 section.
Further, as shown in FIG. 3, a PCR system is disclosed where the polymerase chain reaction is performed by continuously flowing a biochemical fluid, such as a PCR fluid, in concentric circles along different temperature zones (Proc. Miniaturized Total Analysis Systems (uTAS 2001), Louisiana State University, Steven A. Soper et al., pp. 459-461). In this system, a flow path becomes shortened as one complete cycling is repeated. Thus, the flow rate of the biochemical fluid should be accurately controlled in order to follow a temperature profile.